Lacustrine carbonate rocks,distributed mainly at the upper part of the 4th Memberand the middle and lower parts of the 1st Member in the Shahejie Formation,are impor-tant Eogene reservoirs in Bohai Bay Basin.

• 湖相碳酸盐岩是渤海湾盆地下第三系的重要油气储集层,主要分布在沙河街组四段上部和一段中、下部。